Refrigerator including ice maker and method for collecting defrost water of the same

ABSTRACT

Embodiments of the present invention provide a refrigerator, comprising a main body having a food storage compartment therein, a door installed on the main body and having an ice compartment therein and for opening and closing the food storage compartment, a compressor, a condenser, and an expansion valve that are installed in the door, an ice maker installed in the ice compartment, the ice maker comprising a tray configured to receive and contain water therein, and a refrigerant pipe line coupling the compressor, the condenser, and the expansion valve to each other and configured to cool the tray by conduction, and wherein the ice maker further comprises a heater disposed on a perimeter of the tray and a drain duct disposed below the tray and configured to collect defrost water, and wherein a portion of the heater extends into the drain duct.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Korean PatentApplication No. 10-2015-0086082, filed on Jun. 17, 2015, the disclosureof which is incorporated herein in its entirety by reference.

FIELD OF THE INVENTION

Embodiments of the present invention generally relate to a refrigeratorincluding an ice maker and a method for collecting defrost water in therefrigerator.

BACKGROUND OF THE INVENTION

Refrigerators store food at a temperature below the ambient temperatureof the compartment. Refrigerators provide freezing storage or coldstorage of food according to the type of food.

The internal space a refrigerator is cooled by continuously suppliedcold air. Cold air is continuously generated by heat exchange ofrefrigerant through a cooling cycle including compression, condensation,expansion, and evaporation. Cold air is uniformly supplied into theinternal space of the refrigerator by convection, whereby food in therefrigerator can be stored at a desired temperature.

Generally, a main body of the refrigerator has a rectangularparallelepiped structure that is open on a front surface thereof. Arefrigerating compartment and a freezing compartment are within the mainbody. A refrigerating compartment door and a freezing compartment doorare disposed on the front surface of the main body and allow selectiveopening or closing the front opening of the refrigerator. A plurality ofdrawers, shelves, and storage boxes may be disposed in the internalspace formed in the refrigerator so that different kinds of food can bestored under optimal conditions.

Traditionally, top mount refrigerators, in which the freezingcompartment is above the refrigerating compartment, have been commonlyused. Recently, bottom-freezer refrigerators, in which a freezingcompartment is below a refrigerating compartment, were introduced toimprove user convenience. The bottom-freezer refrigerators areadvantageous in that users can more conveniently use the refrigeratingcompartment because the refrigerating compartment, which iscomparatively frequently used, is in an upper portion of therefrigerator, while the freezing compartment, which is usedcomparatively less than the refrigerating compartment, is below therefrigerating compartment. However, the bottom-freezer refrigeratorsrequire a user to bend over when removing ice from the freezingcompartment because the freezing compartment is in a lower portion ofthe refrigerator, and thus are inconvenient for the user.

In an effort to overcome the above problem, a bottom-freezerrefrigerator in which an ice dispenser is disposed in a door of arefrigerating compartment disposed in an upper portion of therefrigerator has been released. In this case, an ice maker for producingice may be provided in the refrigerating compartment door or therefrigerating compartment.

The ice maker may include an ice-making assembly which generates ice andincludes an ice tray, an ice bucket for storing ice therein, and atransfer assembly for transferring ice stored in the ice bucket to thedispenser.

Furthermore, an ice-making duct is installed to couple the freezingcompartment with the ice maker. The ice-making duct is installed in aleft or right sidewall of the refrigerating compartment such that an icecompartment is coupled with the freezing compartment through theice-making duct when a door is closed.

Therefore, when the door opens, the ice-making duct is separated fromthe ice compartment. When the door is closed, the ice-making ductcouples with the ice compartment so that cold air (for generating ice)can be supplied from the freezing compartment to the ice compartmentthrough the ice-making duct.

However, the conventional refrigerator has the following problems.

First, the ice-making duct is installed in the left or right sidewall ofthe refrigerating compartment, and thus a separate structure forinsulating the duct is required. Therefore, since the duct requiresspace, the internal capacity of the refrigerator is reduced, and apiping structure of the refrigerator is complex.

Second, only when the door is closed can cold air be transferred fromthe freezing compartment to the refrigerating compartment. When the dooropens, cold air that passes through the ice-making duct is dischargedout of the refrigerator. Therefore, the energy efficiency of therefrigerator is reduced.

Third, ice is produced by indirect cooling using cold air that issupplied from the ice-making duct. Since ice is not directly cooled, theamount of time it takes to produce ice is increased.

Fourth, because the ice maker is maintained at a low temperature, frosteasily forms on the ice maker. However, with conventional refrigeratordesigns, such frost cannot be effectively removed, and the ice makerfrequently malfunctions.

SUMMARY OF THE INVENTION

In view of the above, embodiments of the present invention provide arefrigerator which does not need a separate duct for transferring coldair for producing ice while the ice maker is installed in arefrigerating compartment door, whereby the structure of therefrigerator is reduced, and the internal capacity of the refrigeratorcan be maximized. Furthermore, embodiments of the present inventionprovide a method for collecting defrost water of the refrigerator.

Further, embodiments of the present invention provide a refrigeratorwith an ice compartment that can be cooled regardless of whether thedoor is open or closed, with increased energy efficiency. Theembodiments of the present invention provide a method for collectingdefrost water of the refrigerator.

In addition, embodiments of the present invention provide a refrigeratorin which ice is generated by direct cooling in an ice compartmentinstalled in the door, and a method for collecting defrost water of therefrigerator.

Furthermore, embodiments of the present invention provide a refrigeratorwhich can effectively remove frost formed on an ice maker, and a methodfor collecting defrost water of the refrigerator.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the present invention will become apparentfrom the following description of embodiments given in conjunction withthe accompanying drawings, in which:

FIG. 1 is a perspective view showing a refrigerator with an open door inaccordance with an embodiment of the present invention;

FIG. 2 is a front view illustrating an ice maker of FIG. 1;

FIG. 3 is a perspective view showing a tray and a refrigerant pipe lineof the ice maker of FIG. 1;

FIG. 4 is a bottom view showing the tray and the refrigerant pipe lineof the ice maker of FIG. 1; and

FIG. 5 is a sectional view showing a portion of the internal structureof the ice maker of FIG. 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described indetail with reference to the accompanying drawings which form a parthereof.

In describing the embodiment of the present invention, a detaileddescription of known functions or constructions related to the presentinvention will be omitted to make description of the subject matter ofpresent invention clear.

FIG. 1 is a perspective view a refrigerator with an open door inaccordance with an embodiment of the present invention.

Referring to FIG. 1, a refrigerator 1, in accordance with the embodimentof the present invention, includes a main body 10, a barrier 12, and adoor 20. The main body 10 forms the structure and/or appearance of therefrigerator 1 and is configured for food storage or the like therein.The barrier 12 partitions a food storage space defined in the main body10 into an upper refrigerating compartment R and a lower freezingcompartment F. The door 20 is disposed on a front surface of the mainbody 10 and is configured to be rotatable so that the main body 10 canbe selectively opened or closed by the door 20.

The door 20 includes an ice compartment 22, a machinery compartment 24,and an insulator 26. An ice maker 100 which generates ice is installedin the ice compartment 22. The machinery compartment 24 includes acompressor 242 and a condenser 244. The insulator 26 is disposed betweenthe ice compartment 22 and the machinery compartment 24 and partitionsthe ice compartment 22 from the machinery compartment 24.

In the present embodiment, although the ice compartment 22 is shownformed on the door 20 for selective access to the refrigeratingcompartment R of the main body 10, this does not preclude the case wherethe ice compartment is formed in a door configured to selectively openor close the freezing compartment F.

Furthermore, in the present embodiment, although the structure in whichthe ice compartment 22 is formed in an upper portion of the door 20 andthe machinery compartment 24 is formed in a lower portion of the door 20are described for illustrative purposes, the spirit of the presentinvention is not limited to this structure. For example, the icecompartment 22 may be formed in the lower portion of the door 20, andthe machinery compartment 24 may be formed in the upper portion of thedoor 20.

The insulator 26 may be made of a foam material, e.g., urethane foam,and configured to prevent heat exchange between the ice compartment 22at a low temperature and the machinery compartment at a comparative hightemperature.

The door 20 includes a cover which closes a portion of the door 20 thatfaces the main body 10 so that even when the door 20 is open, the icecompartment 22 and machinery compartment 24 are sealed from the outsideor external environment. The cover functions to insulate an internalspace of the door 20 from an internal space of the main body 10 when thedoor 20 is closed. As such, the cover may include a foam member havingan area corresponding to the entire area of the door 20. However, forthe sake of explanation, illustration of the cover is omitted from FIG.1.

Furthermore, an insulation member is disposed on a perimeter of the door20 to insulate the internal space of the door 20 from the outside.

The compressor 242 and the condenser 244 are disposed in the machinerycompartment 24 of the door 20. Furthermore, an expansion valve (notshown) of a cooling cycle may also be disposed in the machinerycompartment 24. Alternatively, the expansion valve may be disposed inthe insulator 26.

The compressor 242 may be a small or reduced size compressor which issmaller than a typical compressor disposed in the main body of therefrigerator so that the compressor 242 can be installed in a smallspace in the door 20. A representative example of the small-sizedcompressor was proposed in Korean Patent Unexamined Publication No.10-2013-0048817, which is incorporated herein by reference.

The condenser 244 is coupled to a rear end of the compressor 242 by arefrigerant pipe line 248. Gas-phased refrigerant compressed by thecompressor 242 to high-temperature and high-pressure can be changed bythe condenser 244 to a middle-temperature and high-pressureliquid-phased state. Further, the condenser 244 may also be a compact orreduced size condenser so that it can be installed in the internal spaceof the door 20.

The compressor 242 and the condenser 244 are connected to a power supply(not shown) disposed in the main body 10 so that power can be suppliedto the compressor 242 and the condenser 244. Here, cables which couplethe compressor 242 and the condenser 244 to the power supply of the mainbody 10 are disposed in a hinge pipe that forms a rotating shaft of thedoor 20.

A through hole 246, through which the machinery compartment 24 coupleswith the outside when the door 20 opens, is formed in a surface of thedoor 20 that forms the machinery compartment 24. When the door 20 opens,the outside air drawn into the machinery compartment 24 through thethrough hole 246 cools the condenser 244 such that the refrigerant inthe condenser 244 can be condensed. For this, a hole (not shown) isformed in the surface of the condenser 244 to allow the outside air tobe supplied into the condenser 244. A structure for heat exchangebetween the refrigerant and the outside air supplied through the hole isdisposed in the condenser 244.

The refrigerant pipe line 248 connects the compressor 242 to thecondenser 244 and extends from a rear end of the condenser 244 to theice compartment 22, disposed in the upper portion of the door 20,through the insulator 26. The refrigerant pipe line 248 is alsoconnected to the ice maker 100 provided in the ice compartment 22.

The construction of the ice maker 100 installed in the ice compartment22 will be described in detail with reference to FIGS. 2 to 4.

FIG. 2 is a front view illustrating the ice maker of FIG. 1. FIG. 3 is aperspective view showing a tray and the refrigerant pipe line of the icemaker of FIG. 1. FIG. 4 is a bottom view showing the tray and therefrigerant pipe line of the ice maker of FIG. 1. FIG. 5 is a sectionalview showing a portion of the internal structure of the ice maker ofFIG. 1.

Referring to FIGS. 2 to 5, the ice maker 100 may include a casing 110,an ice-making assembly 120, an ice bucket 130, a transfer assembly 140,and an outlet port 150.

A cooling space, in which ice can be produced, is defined in the casing110. The ice-making assembly 120 is disposed in an upper position in thecooling space. The ice bucket 130 is disposed below the ice-makingassembly 120.

The ice-making assembly 120 includes the tray 122 which includes a moldor frame that receives water and forms ice therein, a heater 126 whichis disposed on the perimeter of the tray 122, and a drive unit 124 whichrotates the tray 122 to drop ice from the tray 122 in a downwarddirection. Furthermore, the drive unit 124 operates the heater 126 andheats the surface of the tray 122 for a short time to slightly melt asurface of ice that adheres to the surface of the tray 122, thus makingit easy to remove the ice from the tray 122.

Moreover, the ice-making assembly 120 includes a drain duct 128 whichcollects defrost water W generated when defrosting using the heater 126.

The tray 122 provides space which receives water from a water supplypipe (not shown) or the like and in which the water is cooled to formice. The tray 122 includes in an upper surface thereof a plurality offorming spaces configured for storing water therein. The forming spacescan have a variety of shapes depending on shapes of ice to be produced.The number of forming spaces can also vary.

The tray 122 is preferably made of metal, e.g., aluminum, having highthermal conductivity. As the thermal conductivity of the tray 122 isincreased, a heat exchange rate between the tray 122 and the refrigerantflowing through the refrigerant pipe line is increased.

The lower surface of the tray 122 is in contact with the refrigerantpipe line 248 extending from the machinery compartment 24. A portion ofthe refrigerant pipe line 248 that comes into contact with the tray 122is referred to as contact part 2482. As shown in FIG. 3, the contactpart 2482 may have a “U” shape. The contact part 2482 extends from afirst end of the tray 122, curves roughly 180° around a second end ofthe tray 122, and then is extends toward the first end of the tray 122and connects to the machinery compartment 24.

However, this is only an example. For example, the contact part 2482 mayhave a plurality of curved portions so that refrigerant can flow backand forth several times under the lower surface of the tray 122.

Here, the contact part 2482 may simply come into surface contact withthe lower surface of the tray 122. Alternatively, to enhance heattransfer efficiency, the contact part 2482 may be firmly attached to thelower surface of the tray 122, e.g., by an adhesive, a fastener or thelike.

Therefore, refrigerant that is compressed and condensed in the machinerycompartment 24 is expanded by the expansion valve and thus cooled. Thecooled refrigerant is transferred to the contact part 2482 of therefrigerant pipe line 248. The refrigerant transferred to the contactpart 2482 cools water in the tray 122. The cooled water is phase-changedinto ice.

In other words, the contact part 2482 of the refrigerant pipe line 248and the tray 122 function as a small-sized evaporator in a coolingcycle.

In a conventional refrigerator with the ice maker installed in the door,cold air is generated by heat exchanged between the refrigerant and air,and the generated cold air is supplied to the tray through a cold airduct by a blower or the like. As such, with the conventional technique,an indirect cooling method using heat exchange between a gas and a solidis used to produce ice. Because the efficiency of the heat exchangebetween a gas and a solid is comparatively low, it takes a long time toproduce ice.

However, in the present embodiment, ice is produced by a direct coolingmethod using heat exchange between solids, that is, between therefrigerant pipe line 248 and the tray 122. Therefore, the efficiency ofheat exchange is enhanced, and the time it takes to produce ice ismarkedly reduced.

The produced ice can be dropped, by the drive unit 124, into the icebucket 130 disposed below the ice tray 122. The drive unit 124 heats theheater 126 for a predetermined time so that the surface of ice thatadheres to the surface of the tray 122 can slightly melt. As the surfaceof the ice slightly melts, the ice that had adhered to the surface ofthe tray 122 detaches from the surface of the tray 122.

If the time the heater 126 is heated is excessively long, the ice formedin the tray 122 may be completely melted. Therefore, it is preferablethat time and rate of heat generation are set such that only the surfaceof ice slightly melts. The ice-making assembly 120 may include a controlunit (not shown) which controls the operation of the drive unit 124.

After the operation of heating the tray 122 has been completed, arotating shaft (not shown) of the rotating unit 124 is rotated. Then,the tray 122 is turned upside down such that the upper surface of thetray 122 faces the ice bucket 130. When the tray 122 is rotated to apredetermined angle or more, the tray 122 is twisted by an interferencemember (not shown). Then, pieces of ice that have been in the tray 122fall into the ice bucket 130 by twisting action of the tray 122.

Furthermore, a plurality of ejectors (not shown) may be disposed on therotating shaft and arranged along the length of the rotating shaft sothat ice can be removed from the tray 122 by rotating only the ejectorswithout rotating the entire tray 122.

The heater 126 is disposed on the perimeter of the tray 122 andfunctions to heat the tray 122. The heater 126 may comprise a heatingrod, a portion of which is curved downward to have a “U” shape. Firstand second ends of the heating rod are coupled to the drive unit 124.Thus, the heating rod can selectively generate heat by a controlmechanism of the drive unit 124, thus heating the tray 122.

Furthermore, the U-shaped curved portion of the heater 126 extendsdownward to form a protrusion part 1262. The protrusion part 1262 mayextend from the heating rod to the drain duct 128.

In addition, the heater 126 may be configured such that a lowermost endof the protrusion part 1262 is disposed in the drain duct 128. Theprotrusion part 1262 is disposed adjacent to an end of the tray 122 thatis opposite to a side at which the heater 126 is connected to the driveunit 124.

The heater 126 having the above-mentioned construction functions notonly to slightly melt the surface of ice in the tray 122 and makeremoval of the ice from the tray 122 easy, but also to heat the interiorof the ice maker 100 when ice production is interrupted and thus defrostthe interior of the ice maker 100. This will be described in more detaillater herein.

The drain duct 128 functions to collect defrost water W, which isgenerated by phase change of frost from a solid to a liquid while theheater 126 defrosts the ice maker 100, and then drains the defrost waterW to the outside. The drain duct 128 is installed below the tray 122 andconfigured such that an end of the drain duct 128 is connected to anexhaust port housing 129 which has a through hole that is coupled withthe outside or exterior environment.

Furthermore, the drain duct 128 is configured such that the bottomthereof declines downward toward the exhaust port housing 129 so thatdefrost water W colleted in the drain duct 128 flows to the exhaust porthousing 129 and discharged to the exterior environment.

Defrost water W collected in the drain duct 128 flows into the exhaustport housing 129, changes into vapor at a position adjacent to theexhaust port housing 129 by heat generated from the protrusion part1262, and then is discharged to the exterior environment.

The transfer assembly 140 functions to transfer ice toward the outletport 150 and includes an auger 142, a motor housing 144, and an augermotor 146.

The auger 142 is a rotatable member which has a screw or a spiral blade.The auger motor 146 rotates the auger 142. The auger 142 is disposed inthe ice bucket 130. Pieces of ice that are in the ice bucket 130 aredisposed between portions of the blades of the auger 142 and thus can betransferred to the outlet port 150 by the rotation of the auger 142. Theauger motor 146 is housed in the motor housing 144.

The outlet port 150 may be coupled to a dispenser (not shown) disposedin the door 20. Depending on the selection of the user, pieces of icecan be transferred by the transfer assembly 140 and supplied to the uservia the dispenser. Although it is not shown in the drawings, a cuttingunit which can cut ice into a predetermined size may be disposed in theoutlet port 150.

The operation and effect of the refrigerator 1 in accordance with thepresent embodiment having the above-mentioned construction will bedescribed below.

In the refrigerator 1 in accordance with the present embodiment,refrigerant flowing along the refrigerant pipe line 248 can be cooledwhile passing through the compressor, the condenser, and the expansionvalve that are installed in the door 20 configured for openably closingthe main body 10. The cooled refrigerant is supplied to the contact part2482 of the refrigerant pipe line 248 that makes contact with the tray122. Thus, the tray 122 is directly cooled by the refrigerant.

Water can be supplied to the tray 122 by a water supply means (notshown). Water supplied to the tray 122 is cooled by refrigerant providedto the contact part 2482 and thus changes phase to produce ice.

Here, refrigerant flows to the contact part 2482 by compressive forceprovided by the compressor 242.

The ice produced in the tray 122 falls downward by the operation of thedrive unit 124 and becomes stored in the ice bucket 130 disposed belowthe tray 122.

Furthermore, refrigerant that has been transferred to the contact part2482 via the expansion valve and has received heat from the tray 122 istransferred again to the machinery compartment 24 through therefrigerant pipe line 248. The refrigerant transferred to the machinerycompartment 24 is supplied to the compressor 242 so that it can bere-cooled through a cooling cycle.

The interior of the ice maker 100 is usually maintained below zerodegrees to produce ice. Therefore, when outside air enters the ice maker100, vapor in the outside air is condensed and solidified, thus formingfrost. Such frost forms on the surfaces of different kinds of devices inthe ice maker 100, thereby potentially causing malfunction or failure ofthe devices of the ice maker 100.

To defrost the ice maker 100, the heater 126 generates heat to changesolid-phased frost into a liquid phase and then discharges it to theexterior environment. Here, although frost may be partially removed whenthe heater 126 generates heat to melt the surface of ice produced in thetray 122, operating the heater 126 for a short time may not be enough toremove the frost if a large amount of frost has formed over a longperiod of time.

Given this, the ice maker 100 may be operated in two modes, that is, anice-making mode and a maintenance mode. In the ice-making mode, ice isproduced. In the maintenance mode, while the cooling cycle in the door20 is interrupted, the drive unit 124 operates the heater 126 togenerate heat. Frost that has formed on the devices, including the tray122 provided in the ice maker 100, is changed into liquid by heatgenerated from the heater 126 and thus is removed from the devices.

Defrost water W, which is generated by phase change of frost, iscollected in the drain duct 128. Further, defrost water W collected inthe drain duct 128 is changed into vapor by heat emitted from theprotrusion part 1262 of the heater 126 that extends into the drain duct128. The vapor moves to the exhaust port housing 129 and then isdischarged out of the exhaust port housing 129.

Under normal conditions, the ice maker 100 is operated in the ice-makingmode to produce ice. The maintenance mode of the ice maker 100 isperiodically operated for a preset time. However, this is only oneexample of a method of controlling the maintenance mode. In other words,the method of controlling the maintenance mode of the ice maker 100 canbe changed in various forms without departing from the scope of theinvention.

As described above, in accordance with the present invention, the pipingstructure of the refrigerator is reduced. The internal capacity of therefrigerator is increased, whereby space efficiency is increased.Furthermore, energy efficiency for cooling is improved, so that the timeit takes to produce ice is reduced. In addition, the present inventioncan effectively defrost the ice maker.

While a refrigerator in accordance with the invention have been shownand described with respect to the exemplary embodiment, embodiments ofthe present invention is not limited thereto. It will be understood bythose skilled in the art that various changes and modifications may bemade without departing from the scope of the invention as defined in thefollowing claims.

Accordingly, the scope of the present invention should be interpretedbased on the following appended claims, and all technical spirits withinan equivalent range thereof should be construed as being included in thescope of the present invention.

What is claimed is:
 1. A refrigerator, comprising: a main body having afood storage compartment therein; a door installed on the main body andcomprising an ice compartment therein and for opening and closing thefood storage compartment; a compressor, a condenser, and an expansionvalve disposed in the door; an ice maker disposed in the icecompartment, the ice maker comprising a tray configured to receive andcontain water therein; and a refrigerant pipe line configured to couplethe compressor, the condenser, and the expansion valve to each other andconfigured to cool the tray by conduction; and wherein the ice makerfurther comprises: a heater disposed on a perimeter of the tray; and adrain duct disposed below the tray and configured to collect defrostwater, and wherein a portion of the heater extends into the drain duct.2. The refrigerator of claim 1, wherein the tray functions as anevaporator of a cooling cycle for producing ice in the ice maker.
 3. Therefrigerator of claim 1, wherein at least a portion of the refrigerantpipe line is configured to contact a lower surface of the tray.
 4. Therefrigerator of claim 1, wherein the heater comprises a heating rod witha protrusion part extending from a portion of the heating rod into thedrain duct.
 5. The refrigerator of claim 1, further comprising amachinery compartment disposed in the door, wherein the machinerycompartment and the ice compartment are partitioned from each other byan insulator, and wherein the compressor and the condenser are disposedin the machinery compartment.
 6. A method for collecting defrost waterof a refrigerator, the method comprising: interrupting an ice-makingoperation of an ice maker disposed in a door of the refrigerator;driving a heater disposed on a perimeter of a tray, the tray disposed inthe ice maker and configured to receive and contain water therein, andremoving frost formed on the tray of the ice maker; and collectingdefrost water, formed by phase change of the frost, in a drain duct intowhich at least a portion of the heater extends.
 7. An apparatuscomprising: an ice maker disposed in an ice compartment, the ice makercomprising a tray configured to receive and contain water therein; and arefrigerant pipe line configured to couple a compressor, a condenser,and an expansion valve to each other and configured to cool the tray byconduction; and wherein the ice maker further comprises: a heaterdisposed on a perimeter of the tray; and a drain duct disposed below thetray and configured to collect defrost water, and wherein a portion ofthe heater extends into the drain duct.
 8. The refrigerator of claim 7,wherein the tray functions as an evaporator of a cooling cycle forproducing ice in the ice maker.
 9. The refrigerator of claim 7, whereinat least a portion of the refrigerant pipe line is configured to contacta lower surface of the tray.
 10. The refrigerator of claim 7, whereinthe heater comprises a heating rod with a protrusion part extending froma portion of the heating rod into the drain duct.
 11. The refrigeratorof claim 7, further comprising a machinery compartment disposed in thedoor, wherein the machinery compartment and the ice compartment arepartitioned from each other by an insulator, and wherein the compressorand the condenser are disposed in the machinery compartment.